JPH0245160Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to the mouth structure of an aluminum tube. More specifically, the present invention relates to a mouth structure of an aluminum tube (hereinafter simply referred to as an aluminum tube) that can prevent leakage of contents.

[Prior Art] Conventionally, the stopper for the mouth of an aluminum tube was done by screwing together a male screw threaded directly on the outer periphery of the aluminum tube mouth body and a female thread threaded on the inner periphery of the cap. There is. However, with this type of stopper method, the contents are blocked at the threaded part, so even if the content does not leak to the outside, the content will adhere to the threaded part of the screw, and the adhering content will leak into the medium. The disadvantage was that it caused stains.

Therefore, a mouth structure was developed in which an inner stopper was interposed between the mouth body of the aluminum tube and the cap. As such a mouth structure, for example, the structure shown in FIG. 4 is adopted in commercially available products. In this case, an annular locking part 23 is formed on the lower outer periphery of the mouth body 21 of the aluminum tube by cutting (plastic processing) the lower end 24 (indicated by the two-dot chain line in FIG. 4) of the mouth body 21. On the other hand, an annular recess 25 that engages with the locking part 23 is formed on the inner periphery of the inner plug body 22, and the inner plug body An annular projection 27 that projects downward is formed on the upper edge 26 of 22 . And inner plug body 2
2 into the spout main body 21, the annular recess 25 of the inner plug body 22 locks into the locking portion 2 of the spout main body 21.
3, the inner plug body 22 is fitted into the mouth body 21, and the protrusion 27 is configured to come into contact with the upper end surface of the mouth body 21.

[Problem to be solved by the invention] However, in the conventional example, the mouth body 21
If the distance between the upper end surface and the locking portion 23 is even slightly shorter than the distance between the tip of the protrusion 27 of the inner plug body 22 and the recess 25, there will be a gap between the protrusion 27 and the upper end surface 28 of the mouth body 21. There is a problem in that a completely sealed state cannot be obtained because of this.

Furthermore, when the inner plug body 22 is driven into the mouth main body 21, the inner circumferential surface of the inner plug body 22 may be damaged by the edges or knurling-shaped convex portions of the upper end surface 28 of the inner plug body 21. 22 and mouth main body 21
Another disadvantage is that the seal between the two is not sufficiently sealed.

In order to eliminate such drawbacks, in the process of arriving at the present invention, the present inventor curled the tip of the mouth body 31 of the aluminum tube as shown in FIG. It was also devised and studied to engage the annular recess 34 above the inner periphery of the inner plug body 33 and seal at that part at the same time. However, in such a structure, the curl forming part 32 is thin, so the strength is poor, and there is a drawback that the curl forming part 32 buckles or deforms when the inner plug body 33 is driven into the mouth main body 31 after annealing.
Furthermore, there is a problem in that the curling process is difficult for tubes with small diameters. Therefore, the present inventor continued his research without disclosing the structure of the mouth.

The present invention eliminates the above-mentioned drawbacks and has an aluminum tube mouth structure that can completely seal between the mouth body and the inner plug body, thereby preventing the contents from leaking. The purpose is to provide

[Means for Solving the Problems] The mouth structure of the aluminum tube of the present invention consists of a mouth body of the aluminum tube and a synthetic resin inner stopper that is tightly fitted into the mouth body. an annular convex portion having a semicircular cross section is formed on the outer periphery of the distal end of the mouth main body, and a lower peripheral surface of the annular convex portion is tapered, and the inner plug body An annular recess that can fit into the annular projection is formed at the upper end of the inner periphery, and a locking portion that can engage with the lower peripheral surface of the annular projection is formed immediately below the annular recess, and The upper circumferential surface of the locking portion is tapered and has a threaded groove formed on its outer circumference.

[Function] In the present invention, when the inner plug body is driven into the tip of the mouth body, the annular concave part of the inner plug body fits into the annular convex part of the mouth body, and the locking part of the inner plug body fits into the annular convex part of the mouth body. It engages with the lower surface of the annular convex part of the part main body, and the inner plug body cannot be removed.

At this time, the lower surface of the annular convex part of the mouth body is tapered and the upper surface of the locking part of the inner plug body is also tapered, so that the inner plug body is guided so as to be deeply inserted. . Therefore, even if the annular recess of the inner stopper is larger than the annular projection of the mouth main body, the inner surface of the annular recess will surely come into close contact with the outer surface of the annular projection.

Therefore, the present invention provides high sealing performance.

[Example] Next, an example of the mouth structure of an aluminum tube of the present invention will be described based on the drawings, but the present invention is not limited to this example.

Fig. 1 is a partially cutaway schematic front view showing an embodiment of the aluminum tube according to the present invention, Fig. 2 is an enlarged schematic front view of the mouth main body of the aluminum tube, and Fig. 3 shows the mouth structure of the present invention. FIG. 2 is a schematic cross-sectional view for explanation.

In FIG. 1, 1 is an aluminum tube, 2 is an aluminum tube body, and the tube body 2 has a shoulder portion 3 and a mouth body 4. As shown in FIGS. 2 and 3, an annular convex portion 5 having a semicircular cross section is formed on the outer periphery of the tip of the mouth main body 4 of the tube body 2. As shown in FIGS. The annular convex portion 5 is formed by post-cutting a portion 6 (indicated by a two-dot chain line in FIG. 3) of the cylindrical upper outer periphery formed during impact molding of the mouth main body 4. Ru. Further, the lower circumferential surface of the annular convex portion 5 is formed to be inclined in a tapered shape. A knurled convex portion 7 extending in the axial direction is formed on the lower outer periphery of the mouth main body 4.

An inner plug body 8 made of synthetic resin (for example, synthetic resin such as polyethylene or polypropylene) is fitted onto the outer periphery of the mouth main body 4 . Such inner plug body 8
An annular recess 9 that can fit into the annular protrusion 5 of the mouth main body 4 is formed at the upper end of the inner periphery of the mouth body 4 , and the mouth is connected to the annular recess 9 immediately below the annular recess. A locking portion 10 that can engage with the lower peripheral surface of the annular convex portion 5 of the portion main body 4 is formed. This locking part 10
The upper circumferential surface is tapered and inclined. On the other hand, a large number of recesses 11 are formed below the inner circumference of the inner plug body 8, which can engage with the knurled protrusions 7 of the mouth main body 4.

The annular concave portion 9, locking portion 10, and convex portion 11 are formed under the annular convex portion 5 and the annular convex portion 5 of the spout body 4 by driving the inner plug body 8 into the spout body 4, respectively. It is engaged with the side circumferential surface and the knurled convex portion 7, thereby preventing the inner plug body 8 from shifting in the axial and circumferential directions. Further, a round thread groove 13 into which the cap 12 is screwed is formed on the outer periphery of the inner plug body 8. Note that the lining material may be interposed between the mouth main body 4 and the inner plug body 8 so as to substantially form a layer. In that case, the opening body 4
Leakage of the contents from the gap between the inner plug body 8 and the inner plug body 8 can be further prevented.

The mouth structure of the aluminum tube configured as described above is composed of the tip portion of the aluminum tube 1, that is, the lower circumferential surface of the annular convex portion 5 of the mouth body 4 and the upper circumferential surface of the locking portion 10 of the inner plug body 8. are in close contact with each other due to the guiding action of the tapered surface, so that the annular convex portion 5 and the annular recess 9 are in close contact with each other. Therefore, there is no variation in the sealing state due to dimensional errors during molding (including post-cutting) as in the past, and leakage of the contents can be completely prevented. Furthermore, since the outer circumferential surface of the annular convex portion 5 of the mouth body 4 remains in an impact-molded state, the accuracy of the outer diameter dimension is high, and therefore the relationship between the mouth body 4 and the inner plug body 8 is high. The seal between the parts becomes even higher. Further, as shown in FIG. 3, the upper outer diameter of the mouth main body 4 is formed to be smaller than the lower outer diameter thereof, and the upper end surface of the mouth main body 2 is formed smoothly with a semicircular cross section. Since the locking portion 10 of the inner plug body 8 is provided above the inner circumference, the inner circumferential surface of the inner plug body 8 is Also, the annular recess 9 of the inner plug body 8, which is a sealing portion, is less likely to be scratched, and therefore the seal between the mouth main body 4 and the inner plug body 8 is more securely sealed.

In addition, in the present invention, in order to eliminate an incompletely fitted state caused by the shoulder 3 of the spout main body 4 and the hem 14 of the inner plug body 8 coming into contact, the shoulder of the spout main body 4 is 3 and the hem 14 of the inner plug body 8 is preferably provided with a gap.

Further, in the embodiment described above, the contact between the inner plug body 8 and the cap 12 is made by connecting the edge 15 formed on the upper end of the inner plug body 8 radially inwardly and the top of the cap 12 inwardly in a hemispherical shape. The contact surface 16 protrudes from the inner plug body 8 and the cap 1.
Of course, other methods utilizing the elasticity of No. 2 can be used.

[Effect of the invention] The mouth structure of the invention can effectively prevent leakage of contents in widely used aluminum tubes, and its practical value is extremely high.

[Brief explanation of the drawing]

Fig. 1 is a partially cutaway schematic front view showing an embodiment of the aluminum tube according to the present invention, Fig. 2 is an enlarged schematic front view of the mouth main body of the aluminum tube, and Fig. 3 shows the mouth structure of the present invention. FIG. 4 is a schematic cross-sectional view for explaining the conventional mouth structure, and FIG. 5 is a schematic cross-sectional view showing an improved example of the mouth structure different from the present invention. Main symbols in the drawing: 1: Aluminum tube, 4, 2
1, 31: mouth main body, 5: annular projection, 7: knurled projection, 8, 22, 33: inner plug body, 9: annular recess, 10: locking portion, 11: recess, 12: cap, 13: Screw groove.

Claims (1)

[Claims for Utility Model Registration] 1. A mouth structure consisting of an aluminum tube mouth body and a synthetic resin inner stopper tightly fitted into the mouth body, comprising: An annular protrusion having a semicircular cross section is formed on the outer periphery of the distal end, and a lower circumferential surface of the annular protrusion is inclined in a tapered shape, and the annular protrusion fits into the inner circumferential upper end of the inner plug body. An annular recess that can be engaged with the annular recess is formed, a locking portion that can engage with the lower circumferential surface of the annular protrusion is formed immediately below the annular recess, and an upper circumferential surface of the locking portion is tapered. The mouth structure of an aluminum tube is characterized by being inclined at a slanted angle and having a screw groove threaded around its outer periphery. 2. The spout structure according to claim 1, wherein a lining material is interposed between the inner plug body and the spout body so as to substantially form a layer.